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User Preference Aware Hierarchical Edge-User Cooperative Caching Strategy

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China Communications 2024年第6期21卷 69-86页

作者： wu Dapeng Yang lin Cui Yaping He Peng Wang Ruyan School of Communications and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China Advanced Network and Intelligent Connection Technology Key Laboratory of Chongqing Education Commission of China Chongqing 400065China Chongqing Key Laboratory of Ubiquitous Sensing and Networking Chongqing 400065China

The emergence of various new services has posed a huge challenge to the existing network *** improve the network delay and backhaul pressure,caching popular contents at the edge of network has been considered as a feasible ***,how to efficiently utilize the limited caching resources to cache diverse contents has been confirmed as a tough problem in the past *** this paper,considering the time-varying user requests and the heterogeneous content sizes,a user preference aware hierarchical cooperative caching strategy in edge-user caching architecture is *** divide the caching strategy into three phases,that is,the content placement,the content delivery and the content *** the content placement phase,a cooperative content placement algorithm for local content popularity is designed to cache contents *** the content delivery phase,a cooperative delivery algorithm is proposed to deliver the cached *** the content update phase,a content update algorithm is proposed according to the popularity of the ***,the proposed caching strategy is validated using the MovieLens dataset,and the results reveal that the proposed strategy improves the delay performance by at least 35.3%compared with the other three benchmark strategies.

关键词： cooperative caching network delay timevarying popularity user preference

Sustained release of vascular endothelial growth factor A and basic fibroblast growth factor from nanofiber membranes reduces oxygen/glucose deprivation-induced injury to neurovascular units

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Neural Regeneration Research 2024年第4期19卷 887-894页

作者： Yifang wu Jun Sun Qi lin Dapeng Wang Jian Hai Department of Neurosurgery Tongji HospitalSchool of MedicineTongji University Department of Pharmacy Institute of Medical SciencesShanghai Jiao Tong University School of Medicine

Upregulation of vascular endothelial growth factor A/basic fibroblast growth factor(VEGFA/b FGF)expression in the penumbra of cerebral ischemia can increase vascular volume,reduce lesion volume,and enhance neural cell proliferation and differentiation,thereby exerting neuroprotective ***,the beneficial effects of endogenous VEGFA/b FGF are limited as their expression is only transiently *** this study,we generated multilayered nanofiber membranes loaded with VEGFA/b FGF using layer-by-layer self-assembly and electrospinning *** found that a membrane containing 10 layers had an ideal ultrastructure and could efficiently and stably release growth factors for more than 1 *** 10-layered nanofiber membrane promoted brain microvascular endothelial cell tube formation and proliferation,inhibited neuronal apoptosis,upregulated the expression of tight junction proteins,and improved the viability of various cellular components of neurovascular units under conditions of oxygen/glucose ***,this nanofiber membrane decreased the expression of Janus kinase-2/signal transducer and activator of transcription-3(JAK2/STAT3),Bax/Bcl-2,and cleaved ***,this nanofiber membrane exhibits a neuroprotective effect on oxygen/glucose-deprived neurovascular units by inhibiting the JAK2/STAT3 pathway.

关键词： brain ischemia brain microvascular endothelial cell nanofiber membrane neurovascular unit

Activatable photoacoustic bioprobe for visual detection of aging in vivo

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Chinese Chemical Letters 2024年第4期35卷 324-329页

作者： Zihong Li Jie Cheng Ping Huang Guoliang wu Weiying lin Institute of Optical Materials and Chemical Biology Guangxi Key Laboratory of Electrochemical Energy MaterialsSchool of Chemistry and Chemical EngineeringGuangxi UniversityNanning 530004China

Aging is a natural physiological process with various challenges, related to the loss of homeostasis within the organism, which is not a disease, but a significantly strong risk factor for multiple diseases, including myocardial infarction, stroke, some age-related cancers, macular degeneration, osteoarthritis, neurodegeneration, and many others. In the body, the main manifestation of aging is cellular aging, which exists within tissues and has a local or global impact on tissue function. However, the lack of effective aging detection tools has always been an issue that cannot be ignored in the field of aging research. Therefore,it is necessary to construct a non-invasive tool for in vivo detection of aging. Here, we show that the photoacoustic probe(LGAL), which has peak excitation and emission wavelengths in the near-infrared optical window, binds in vivo and at high contrast to the hallmark of aging, and allows for the microscopic imaging of aging through the intact mice. Firstly, this tool LGAL has been successfully applied to detect senescence in cells, displaying stronger photoacoustic signals than normal cells. Then, by using the photoacoustic probe, the blood vessels and tissues inside the mice can be visualized. Young and elderly mice exhibit varying intensities of photoacoustic signals, marking the first time a probe has been used to explore the aging of blood vessels and tissues inside the mice. Finally, we monitored the changes in the degree of aging during tumor treatment under photoacoustic(PA) imaging for the first time. As the treatment time increased, the degree of aging of the tumor gradually deepened. We expect the powerful tool could be a noninvasive and powerful tool for the study of aging biology.

关键词： Near-infrared Photoacoustic Aging Senescence Tumor Sa-β-gal

Asymmetric Two-Component Alkenyl Catellani Reaction for the Construction of C—N Axial Chirality

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Chinese Journal of Chemistry 2024年第7期42卷 699-704页

作者： Chenggui wu Ze-shui Liu Yong Shang Chang Liu Shuang Deng Hong-Gang Cheng Hengjiang Cong Yinchun Jiao Qianghui Zhou Sauvage Center for Molecular Sciences Engineering Research Center of Organosilicon Compounds&Materials(Ministry of Education)Hubei Key Lab on Organic and Polymeric OptoElectronic MaterialsCollege of Chemistry and Molecular SciencesThe Institute for Advanced Studiesand TaiKang Center for Life and Medical SciencesWuhan UniversityWuhanHubei 430072China Key Laboratory of Xin'an Medicine Ministry of EducationAnhui University of Chinese MedicineHefeiAnhui 230038China School of Chemistry and Chemical Engineering Hunan University of Science and TechnologyXiangtanHunan 411201China

Herein,we report an asymmetric two-component alkenyl Catellani reaction for the construction of C—N axial chirality through a palladium/chiral norbornene cooperative catalysis and an axial-to-axial chirality transfer *** partially aromatic iodinated 2-pyridones,quinolones,coumarin and uracil substrates react with 2,6-disubstituted aryl bromides with a tethered amide group,to afford a wide variety of polycyclic C—N atropisomers(38 examples,up to 97%e.e.).The obtained C—N axial chirality originates from the preformed transient C—C axial chirality with high *** synthetic utility of this chemistry is demonstrated by facile prepa-ration of complex quinoline and pyridine based C—N atropisomers through a N-deprotection and aromatization *** addi-tion,a remote axial-to-central diastereoinduction process dictated by C—N axial chirality is observed with excellent diastereocontrol.

关键词： Alkenyl Catellani reaction Asymmetric catalysis Atropisomerism Axial-to-axial chirality transfer Heterocycles

Efficient removal of natural organo-chromium(Ⅲ)through selfcirculating decomplex and immobilization with nanoscale zerovalent iron

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Nano Research 2024年第1期17卷 364-371页

作者： Zhicheng Dong Yunyun Xu Can wu Jin Chao Chen Tian Zhang lin School of Metallurgy and Environment Central South UniversityChangsha 410083China Chinese National Engineering Research Center for Control&Treatment of Heavy Metal Pollution Changsha 410083China College of Ecology and Environment Chengdu University of TechnologyChengdu 610059China School of Environment and Energy The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters(Ministry of Education)South China University of TechnologyGuangzhou 510006China

Organo-chromium(III)complex is one of the chromium contaminant species,which would transform to high-toxic Cr(VI)during migrating in the *** natural organo-chromium(III)(NOCr)is difficult to remove by traditional degradation or precipitation methods,due to its high stability and ***,we demonstrated a novel NOCr removing method by transforming it to certain structures similar to Cr-Fe minerals in nature,through a self-circulating decomplex and immobilization mechanism with nano zero-valent iron(nZVI).Taking chromium glycinate(Cr-Gly)as a probe,nZVI showed a high Cr removal efficiency of 99.4%under ambient *** removal process included three stages of adsorption,decomplexation,and ***-Gly was first adsorbed on the surface of nZVI by chemisorption of the oxide ***,the adsorbed Cr-Gly was decomplexed and oxidized to Cr(VI)by·OH and 1O_(2),which were generated from molecular oxygen activated by ***,the released Cr(VI)could be in-situ adsorbed and re-reduced to Cr(III),which was further immobilized in form of Cr-O-Fe *** the Cr-O-Fe complexing structure was similar to that of Cr-Fe minerals(such as chromohercynite)in nature,this work explored a novel and efficient NOCr removing method that was potential to weaken chromium pollution in the environment.

关键词： organo-chromium(III) zero-valent iron adsorption decomplexation Cr immobilization

Estimating Critical Clearing Time of Grid Faults Using DA of State-Reduction Model of Power Systems

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 807-820页

作者： Yang Liu Zhongyang Chen Huanjin Yao lin Yi Q.H.wu School of Electric Power Engineering South China University of TechnologyGuangzhou 510640China China Southern Power Grid Research Institute Guangzhou 510663China

This paper proposes a critical clearing time (CCT) estimation method by the domain of attraction (DA) of a state-reduction model of power systems using sum of squares (SOS) programming. By exploiting the property of the Jacobian matrix and the structure of the boundary of the DA, it is found the DA of the state-reduction model and that of the full model of a power system are topological isomorphism. There are one-to-one correspondence relationships between the number of equilibrium points, the type of equilibrium points, and solutions of the two system models. Based on these findings, an expanding interior algorithm is proposed with SOS programming to estimate the DA of the state-reduction model. State trajectories of the full model can be transformed to those of the state-reduction model by orthogonal or equiradius projection. In this way, CCT of a grid fault is estimated with the DA of the state-reduction model. The calculational burden of SOS programming in the DA estimation using the state-reduction model is rather small compared with using the full model. Simulation results show the proposed expanding interior algorithm is able to provide a tight estimation of DA of power systems with higher accuracy and lower time costs.

关键词： Critical clearing time domain of attraction expanding interior algorithm state-reduction model SOS programming

Color-polarization synergistic target detection method considering shadow interference

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Defence Technology（防务技术） 2024年第7期37卷 50-61页

作者： Bin Feng Jinpei Xiao Junchao Zhang lin Li Yunlong wu Qing Ye School of Automation Northwestern Polytechnical UniversityXi'an710072China School of Automation Central South UniversityChangsha410083China State Key Laboratory of Pulsed Power Laser Technology National University of Defense TechnologyHefei230037China

Aiming at the problem of shadow interference in UAV's ground reconnaissance,a color and polarization synergistic target detection method is proposed for anti-shadow interference,based on the influence of two physical characteristics(wavelength and polarization)under different illuminations.A valid fusion strategy is proposed via integrating two separate detection results on color and polarization ***,a local enhancement and recognition module(LER)is introduced to boost the *** on our built dataset,experimental results show that our method achieves mAPof 87.76%,and12.37%higher than that of color image and 14.68%higher than that of polarization image.

关键词： Electro-optical countermeasure Ground reconnaissance Color-polarization Shadow interference Target recognition

Experimental Study of Fuel-Air Mixing and Dilution Jets on Outlet Temperature Distribution in a Small Gas Turbine Combustor

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Journal of Thermal Science 2024年第5期33卷 1883-1896页

作者： CAI Wenzhe wu Jing HU Yingqi YANG Zhiqiang XUE Xin lin Yuzhen National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics Research Institute of Aero-EngineBeihang UniversityBeijing 100191China Beijing Institute of Power Machinery Beijing 100074China School of Energy and Power Engineering Beihang UniversityBeijing 100191China

Experimental analysis was conducted to study the impact of fuel-air mixing and dilution jet on the temperature distribution in a small gas turbine combustor using various optical diagnostic *** strength and velocity of the swirler at the venturi exit were adjusted to modify the fuel-air mixture,which is presumed to dominate the heat release of the main combustion ***,the dilution hole configuration,including the number and size of the holes,was varied to investigate the dilution effect on outlet temperature *** optical diagnostic techniques,such as particle image velocimetry,planar Mie scattering,and OH~*chemiluminescence,were used to measure the flow field,fuel spray distribution,and flame structure,respectively.A reduction in swirling strength led to a decrease in the average flow rate in the throat,which improved the structure and symmetry of the axial vortex system in the sleeve,enhanced the mixing of fuel and gas in the dome swirling air,and ultimately,improved the temperature uniformity of the heat release *** to larger and sparse dilution jets,smaller and dense dilution jets tended to generate hot spots shifted towards the radial middle area.

关键词： small gas turbine combustor fuel-air mixing outlet temperature distribution dilution jet laser diagnostics

3D interlocked all-textile structured triboelectric pressure sensor for accurately measuring epidermal pulse waves in amphibious environments

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Nano Research 2024年第3期17卷 1923-1932页

作者： Shaobo Si Chenchen Sun Yufen wu Jingjing Li Han Wang Yinggang lin Jin Yang Zhong lin Wang Department of Optoelectronic Engineering Key Laboratory of Optoelectronic Technology and Systems Ministry of EducationChongqing UniversityChongqing 400044China College of Physics and Electronic Engineering Chongqing Normal UniversityChongqing 401331China Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 100083China School of Materials Science and Engineering Georgia Institute of TechnologyAtlantaGA 30332USA

The performance degradation and even damage of the e-textiles caused by sweat,water,or submersion during all-weather health monitoring are the main reasons that e-textiles have not been commercialized and routinized so ***,we developed an amphibious,high-performance,air-permeable,and comfortable all-textile triboelectric sensor for continuous and precise measurement of epidermal pulse waves during full-day *** on the principle of preparing gas by acid-base neutralization reaction,a one-piece preparation process of amphibious conductive yarn(ACY)with densely porous structures is *** innovative three-dimensional(3D)interlocking fabric knitted from ACYs(0.6 mm in diameter)and polytetrafluoroethylene yarns exhibit high sensitivity(0.433 V·kPa^(-1)),wide bandwidth(up to 10 Hz),and stability(>30,000 cycles).With these benefits,98.8%agreement was achieved between wrist pulse waves acquired by the sensor and a high-precision laser ***,the polytetrafluoroethylene yarn with good compression resilience provides sufficient mechanical support for the contact separation of the ***,the unique skeletonized design of the 3D interlocking structure can effectively relieve the water pressure on the sensor surface to obtain stable and accurate pulse waves(underwater depth of 5 cm).This achievement represents an important step in improving the practicality of e-textiles and early diagnosis of cardiovascular diseases.

关键词： triboelectric pressure sensor amphibious fabric interlocking fabric pulse wave measurement one-piece preparation method